This invention relates to a method and apparatus for the duplicate injection molding of a precisely dimensioned frame around the periphery of a flat or curved object, the measurements of which are subject to dimensional variations or tolerances. Such a duplicate molded frame makes it possible to achieve the specified measurements for the overall perimeter and for the thickness of the assembled object and frame.
More particularly, but not exclusively, the invention concerns the body panels of automobiles, such as the glass panels for the front and rear windshields, or other glass panels for vehicles or buildings that are to be set into an opening in a wall or other surface, where the dimensions of the opening are exact.
It is well known that mass produced parts show considerable dimensional variation from one to the other, and from specifications. These variations are due either to the process of manufacture used, particularly if no machining is involved, to drift over time in the adjustment parameters of the tools used, and/or to wear in these tools. When these parts must be assembled into a whole with other parts, there are difficulties in obtaining a proper assembly as a result of the dimensional variations between the specifications and the real measurements of the parts being assembled.
This poses the problem of carrying out such assemblies, even using parts or panels with dimensions that are smaller than the dimensions into which they are to be set.